In industrial and commercial laundry facilities, textile materials such as sheets, towels, wipes, garments, table cloths, etc. are often laundered at elevated temperatures and at alkaline pH. Alkalinity can be provided through a single alkaline detergent, or alternatively alkalinity can be provided from one product, while the other detergent components, including surfactants, chelants, water conditioners and/or other detergent materials are provided in a second product. In other markets, textile materials are often laundered with neutral detergents with a separate alkaline product combined in a wash. Detergents can be combined in a laundry application with various additional components such as bleaches, brightening agents, anti-redeposition agents, etc. that are used to enhance the appearance of the resulting textile materials. Various additional components may optionally be dosed separately from the alkaline detergent, and will either be mixed together in the laundry wash bath or in a separate laundry bath liquor. For example, in some laundry applications there are discrete dosing and rinsing steps where there is a rinse between a detergent and bleach step. In other laundry applications, such as a tunnel washer, various addition steps employing mixing of the components. In each of these applications at the end of the cycle, the textile materials that have been treated with an alkaline detergent are typically treated with a commercial or industrial sour composition that contains acid components for neutralizing alkaline residues on the fabric to enhance skin compatibility.
In a conventional, industrial laundry washing facility, textile materials can be subjected to several treatment steps in an industrial sized laundry washing machine to provide antimicrobial efficacy. Exemplary treatment steps include a presoak step, a wash step that often occurs at a pH of about 11 to 12, a rinse step and/or multiple rinse steps for the removal of soil containing wash liquor which incrementally lower the pH, and a sour step that brings the final pH to about 5 to 7, and an extract step that often involves spinning the textiles and/or pressing the textiles in a tunnel application to remove water. An antimicrobial composition can be applied concurrently with the detergent, such as an all-in-one product for powders and solids or concurrent dosing of distinct products, immediately following the detergent step, following a rinse and drain, and/or during the sour step where it is afforded a minimum contact time in the absence of other cleaning chemicals. Laundry applications can vary between concurrent dosing of detergent and other cleaning chemicals.
There remains a need to improve the industrial laundry washing techniques and provide a reduction in processing time, cost of materials, materials consumption, energy costs, and water consumption. Accordingly, it is an objective of the methods to improve on one or more of these aspects of laundry washing techniques.
An object of the methods to enhance bleaching efficacy for laundry and other applications employing an antimicrobial step before a bleaching step.
A further object of the methods is to provide a low oxygen bleaching system for the sanitizing or antimicrobial disinfecting methods of use. The low oxygen peroxyformic acid compositions are suitable for use with chlorine bleach. An object of the methods is to enable bleaching efficacy of a chlorine bleach in combination with the peroxyformic acid composition for bleaching of laundry articles. In the presence of the peroxyformic acid composition the chlorine bleach is allowed to provide bleaching efficacy, as opposed to the interference with bleaching efficacy that customarily takes place with oxygen-containing (or greater oxygen-containing) antimicrobials. Low hydrogen peroxide containing peroxyformic acid compositions are beneficially provided in the bleaching of laundry methods to avoid such interaction with chlorine as is customary with peroxycarboxylic acids, such as peroxyacetic acid formulations. In still further benefits and aspects of the methods, peroxyformic acid compositions, regardless of the hydrogen peroxide content, provide benefits when combined with chlorine in comparison to other peroxycarboxylic acids (e.g. peroxyacetic acid) due to the improved efficacy enabling lower dosing of the peroxyformic acid composition as well as rapid degradation of the peroxyformic acid composition.
Other objects, advantages and features of the methods will become apparent from the following specification taken in conjunction with the accompanying drawings.